This patent application claims priority to European Patent Application Serial No. 18305826.2, filed Jun. 28, 2018, which is incorporated herein by reference in its entirety.
The following description relates to elevator systems and, more specifically, to elevator systems having electronic safety actuators (ESAs).
Elevator systems generally make use of governor systems to monitor the rate of descent of an elevator car and to engage safety devices in an event the elevator car descends at an excessive speed. A typical governor system would be responsive to elevator car speeds through couplings, such as a governor sheave coupled to a rope that is attached to an elevator car, whereby the rope transmits elevator car speed to the governor. When a predetermined speed is exceeded, conventional actuators, such as centrifugal flyweights, trigger a first set of switches. If the car speed continues to increase, additional mechanics engage to impede elevator car movement.
In modern elevator systems, ESAs may replace governor systems and operate by electronically engaging safeties. The safeties are normally maintained at a distance from guiderail blades so that the elevator cars can move freely. This distance maintenance may be provided by gibs or rollers. While the gibs or rollers can provide guidance for the ESAs, they are prone to wear over time and may produce undesirable noise and vibration.
According to an aspect of the disclosure, an elevator car is provided and includes a car frame which translates along a guide rail during ascents or descents, a safety disposed along the car frame to selectively engage with the guide rail to selectively permit vertical elevator car movement, an electronic safety actuator (ESA) and a control system. The ESA is configured to actuate the safety and includes an ESA body secured to the car frame with horizontal maneuverability and defining a groove through which the guide rail translates during the vertical elevator car movement, a magnetic guide operably disposed within the groove to exert magnetic force on the guide rail and a sensor disposed within the groove to sense horizontal distance between the guide rail and corresponding portions of the ESA body. The control system is configured to control the magnetic guide to exert a magnetic force in accordance with reading of the sensor to maneuver the ESA body horizontally.
In accordance with additional or alternative embodiments, the car frame, the safety and the ESA are provided in sets on opposite elevator car sides.
In accordance with additional or alternative embodiments, the ESA includes a linkage coupled to the ESA body and the safety for actuation of the safety.
In accordance with additional or alternative embodiments, the ESA body defines horizontal grooves through which a fastener extends into the car frame.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more electro-magnets respectively disposed in at least one of an upper portion of the groove, a lower portion of the groove and a middle portion of the groove.
In accordance with additional or alternative embodiments, the magnetic guide further includes one or more permanent magnets respectively disposed to magnetically oppose the one or more electro-magnets.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more electro-magnets disposed in an upper portion of the groove and one or more electro-magnets disposed in a lower portion of the groove.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more permanent magnets disposed in the upper portion of the groove to magnetically oppose the one or more permanent magnets therein and one or more permanent magnets disposed in the lower portion of the groove to magnetically oppose the one or more permanent magnets therein.
In accordance with additional or alternative embodiments, the magnetic guide includes a first pair of magnetic guides disposed on opposite sides of an upper portion of the groove and a second pair of magnetic guides disposed on opposite sides of a lower portion of the groove.
In accordance with additional or alternative embodiments, the control system is configured to control the magnetic guide to increase the magnetic force when the readings of the sensor are indicative of the horizontal distance decreasing.
According to an aspect of the disclosure, an electronic safety actuator (ESA) is provided for actuating an elevator car safety. The ESA includes an ESA body vertically secured to the elevator car with horizontal maneuverability, the ESA body defining a groove through which a guide rail, along which the elevator car moves vertically, is translatable, a magnetic guide operably disposed within the groove to exert magnetic force on the guide rail, a sensor disposed within the groove to sense horizontal distance between the guide rail and corresponding portions of the ESA body and a control system configured to control the magnetic guide to exert the magnetic force in accordance with readings of the sensor to maneuver the ESA body horizontally.
In accordance with additional or alternative embodiments, the ESA body is formed to define horizontal grooves through which a fastener extends.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more electro-magnets respectively disposed in at least one of an upper portion of the groove, a lower portion of the groove and a middle portion of the groove.
In accordance with additional or alternative embodiments, the magnetic guide further includes one or more permanent magnets respectively disposed to magnetically oppose the one or more electro-magnets.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more electro-magnets disposed in an upper portion of the groove and one or more electro-magnets disposed in a lower portion of the groove.
In accordance with additional or alternative embodiments, the magnetic guide includes one or more permanent magnets disposed in the upper portion of the groove to magnetically oppose the one or more permanent magnets therein and one or more permanent magnets disposed in the lower portion of the groove to magnetically oppose the one or more permanent magnets therein.
In accordance with additional or alternative embodiments, the magnetic guide includes a first pair of magnetic guides disposed on opposite sides of an upper portion of the groove and a second pair of magnetic guides disposed on opposite sides of a lower portion of the groove.
In accordance with additional or alternative embodiments, the control system is configured to control the magnetic guide to increase the magnetic force when the readings of the sensor are indicative of the horizontal distance decreasing.
According to an aspect of the disclosure, a method of operating an electronic safety actuator (ESA) of an elevator car is provided. The method includes disposing a guide rail for translation within a groove defined in an ESA body, which is vertically secured to the elevator car with horizontal maneuverability, generating magnetic forces that are directed horizontally to maintain respective distances between the guide rail and complementary surfaces of the ESA body, sensing the respective distances and controlling the generating of the magnetic forces to maneuver the ESA body horizontally to maintain the respective distances.
In accordance with additional or alternative embodiments, the generating of the magnetic forces includes at least one of generating repulsive magnetic forces in opposite horizontal directions at an upper portion of the groove, generating repulsive magnetic forces in opposite horizontal directions at a lower portion of the groove and generating repulsive magnetic forces in opposite horizontal directions at a middle portion of the groove.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the disclosure, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
As will be described below, generally reduced-contact levitation of an ESA body relative to guide rails is provided by the control of electro-magnetic forces by electro-magnetic actuators (EMAs). One or more position sensors (e.g., inductive sensors) are used to determine a distance between each EMA and the corresponding guide rail and the control system modifies/modulates the force of each EMA accordingly in order to avoid an incident in which any ESA body touches the guide rail and to guarantee that a certain amount of clearance is maintained.
The roping 107 engages the machine 111, which is part of an overhead structure of the elevator system 101. The machine 111 is configured to control movement between the elevator car 103 and the counterweight 105. The position encoder 113 may be mounted on an upper sheave of a speed-governor system 119 and may be configured to provide position signals related to a position of the elevator car 103 within the elevator shaft 117. In other embodiments, the position encoder 113 may be directly mounted to a moving component of the machine 111, or may be located in other positions and/or configurations as known in the art.
The controller 115 is located, as shown, in a controller room 121 of the elevator shaft 117 and is configured to control the operation of the elevator system 101, and particularly the elevator car 103. For example, the controller 115 may provide drive signals to the machine 111 to control the acceleration, deceleration, leveling, stopping, etc. of the elevator car 103. The controller 115 may also be configured to receive position signals from the position encoder 113. When moving up or down within the elevator shaft 117 along guide rail 109, the elevator car 103 may stop at one or more landings 125 as controlled by the controller 115. Although shown in a controller room 121, those of skill in the art will appreciate that the controller 115 can be located and/or configured in other locations or positions within the elevator system 101.
The machine 111 may include a motor or similar driving mechanism. In accordance with embodiments of the disclosure, the machine 111 is configured to include an electrically driven motor. The power supply for the motor may be any power source, including a power grid, which, in combination with other components, is supplied to the motor.
Although shown and described with a roping system, elevator systems that employ other methods and mechanisms of moving an elevator car within an elevator shaft, such as hydraulic and/or ropeless elevators, may employ embodiments of the present disclosure.
With reference to
In an event the elevator car 201 begins to ascend or descend too quickly, the elevator car 201 also has safety features that can be engaged to slow the elevator car 201 down or to stop it altogether.
With continued reference to
The safeties 230 may each be affixed to the first and second car frame structures 204 and 205 at the opposite sides of the elevator car 201 (although it is to be understood that the safeties 230 can be affixed to a same side or to adjacent sides of the elevator car 201 and that multiple safeties 230 can be affixed to a particular side of the elevator car 201) so that each safety 230 is at least proximate to a corresponding guide rail 210. Each safety 230 is configured engage with the corresponding guide rail 210 or to remain disengaged from the corresponding guide rail 210. When it is engaged, the safety 230 impedes movement of the elevator car 201 along the corresponding guide rail 210 and, when disengaged, the safety 230 permits movement of the elevator car 201 along the corresponding guide rail 210. The safeties 230 are normally disengaged.
The safeties 230 each include a safety body 231, a channel 232 that is defined through the safety body 231 and one or more wedge elements 233. When installed, the corresponding guide rail 210 extends into and through the channel 232 so that the guide rail 210 can translate within the channel 232 as the elevator car 201 ascends or descends. The wedge elements 233 are disposed in or proximate to the channel 232. When the safety 230 occupies the unengaged position, the wedge elements 233 do not engage or at least do not forcefully engage with the portion of the guide rail 210 in the channel 222 via a safety roller or wedge 251 of an ESA tie rod 250 (to be described further below). When the safety 230 occupies the engaged position, the wedge elements 233 engage with the portion of the guide rail 210 in a forceful manner via the safety roller or wedge 251 that is sufficient to impede or prevent the elevator car 201 from ascending or descending. Such engagement is typically frictional and sufficient to slow or stop the elevator car 201 (particularly when each safety 230 occupies the engaged position).
While the wedge elements 233 can be provided as one or more wedge elements 233, the following description will relate only to the case in which a single wedge element 233 is provided in each safety 230. This is done for purposes of clarity and brevity and is not intended to otherwise limit the scope of the disclosure.
The ESAs 240 are respectively coupled to corresponding safeties 230 by the ESA tie rods 250. Each ESA tie rod 250 includes an elongate member 252, an ESA pad 253 at a first end of the elongate member 252 and the safety roller or wedge 251 at a second end of the elongate member. Each ESA 240 includes one or more electromagnetic actuators that are configured to deploy the ESA pad 253 toward the corresponding guide rail 210 when the elevator car 201 ascends or descends excessively fast. As shown in
Each ESA 240 is thus configured to actuate the corresponding safety 230 by deploying the ESA pad 253 toward the corresponding guide rail 210 and includes an ESA body 241. The ESA body 241 is secured to the corresponding one of the first and second car frame structures 204 and 205. The securing of the ESA body 241 is accomplished so as to prevent vertical movement of the ESA body 241 relative to the corresponding one of the first and second car frame structures 204 and 205 while allowing for lateral or horizontal movement of the ESA body 241 relative to the corresponding one of the first and second car frame structures 204 and 205. That is, the ESA body 241 is vertically secured to the corresponding one of the first and second car frame structures 204 and 205 with lateral or horizontal maneuverability.
As shown in
As shown in
With continued reference to
The magnetic guides 260 may include one or more electro-magnets (261-264EM in
The magnetic guides 260 may be provided as first and second sets of magnetic guides. Alternatively, a single set of magnetic guides 260, or two or more sets of magnetic guides may be employed.
In an exemplary case, a first set of magnetic guides may be operably disposed within the upper portion 245 of the guide rail groove 244 and include an upper, first electro-magnetic guide 261EM that is disposed on the first side 247 and an upper, second electro-magnetic guide 262EM that is disposed on the second side 248. A second set of magnetic guides may be operably disposed within the lower portion 246 of the guide rail groove 244 and include a lower, first electro-magnetic guide 263EM that is disposed on the first side 247 and a lower, second electro-magnetic guide 264EM that is disposed on the second side 248. Each magnetic guide 260 may include a ferromagnetic core 2601 and windings 2602 that are energizable to generate the magnetic force.
The sensors 270 may be provided as an upper sensor 271 that is operably disposed within the upper portion 245 of the guide rail groove 244 and a lower sensors 272 that is operably disposed within the lower portion 246 of the guide rail groove 244.
In accordance with further embodiments, additional sensors 270 could be provided as well. For example, two upper sensors 271 and two lower sensors 272 could be provided on either side of the guide rail groove 244 for additional sensing capability or redundancy.
The upper, first electro-magnetic guide 261EM can exert a repulsive magnetic force toward the corresponding guide rail 210, which can be directed and magnified so as to maintain a distance between the corresponding guide rail 210 and the first side 247 in the upper portion 245. The upper, second electro-magnetic guide 262EM can exert a repulsive magnetic force toward the corresponding guide rail 210, which can be directed and magnified so as to maintain a distance between the corresponding guide rail 210 and the second side 248 in the upper portion 245. Thus, the upper, first electro-magnetic guide 261EM and the upper, second electro-magnetic guide 262EM cooperatively operate to maintain the corresponding guide rail 210 substantially close to a center portion between the first and second sides 247 and 248 in the upper portion 245.
The lower, first electro-magnetic guide 263EM can exert a repulsive magnetic force toward the corresponding guide rail 210, which can be directed and magnified so as to maintain a distance between the corresponding guide rail 210 and the first side 247 in the lower portion 246. The lower, second electro-magnetic guide 264EM can exert a repulsive magnetic force toward the corresponding guide rail 210, which can be directed and magnified so as to maintain a distance between the corresponding guide rail 210 and the second side 248 in the lower portion 246. Thus, the lower, first electro-magnetic guide 263 and the lower, second electro-magnetic guide 264EM cooperatively operate to maintain the corresponding guide rail 210 substantially close to a center portion between the first and second sides 247 and 248 in the lower portion 246.
In accordance with further embodiments, fewer or additional magnetic guides 260 could be provided. For example, one or more electro-magnetic guides could be operably disposed in the middle portion 2456 of the guide rail groove 244 in a similar manner as described above. As another example, the upper, first electro-magnetic guide 261EM could be paired with only the lower, second electro-magnetic guide 264EM. In such cases, the upper, first electro-magnetic guide 261EM and the lower, second electro-magnetic guide 264EM act in concert with one another to generate repulsive and/or attractive magnetic forces that maintain the corresponding guide rail 210 substantially close to a center portion between the first and second sides 247 and 248 in the upper and lower portions 245 and 246.
To the extent that one or more of the magnetic guides 260 is a permanent magnet, the permanent magnet can be operably disposed to oppose the magnetic force applied to the corresponding guide rail 210 by one or more proximal electro-magnetic guides. For example, the upper, first electro-magnetic guide 261EM could be opposed by the upper, second permanent magnetic guide 262P and the lower, first electro-magnetic guide 263EM could be opposed by the lower, second permanent magnetic guide 264P. In such cases, the upper, first electro-magnetic guide 261EM and the lower, first electro-magnetic guide 263EM act in concert against the opposing forces of the upper, second permanent magnetic guide 262P and the lower, second permanent magnetic guide 264P to generate repulsive magnetic forces that maintain the corresponding guide rail 210 substantially close to a center portion between the first and second sides 247 and 248 in the upper and lower portions 245 and 246.
As shown in
For example, in an event that the processing unit 281 determines from the readings of the upper sensor 271 that the corresponding guide rail 210 has drifted toward the first side 247 such that the distance between the corresponding guide rail 210 and the first side 247 is less than a predefined distance threshold, processing unit 281 will effectively cause the upper, first magnetic guide 261 to increase the repulsive magnetic force exerted onto the corresponding guide rail 210 as compared to the repulsive force exerted onto the corresponding guide rail 210 by the upper, second magnetic guide 262. This will have the effect of driving the ESA body 241 in the lateral or horizontal directions along the lateral or horizontal grooves 242 toward re-centering the corresponding guide rail 210 in the upper portion 245 of the guide rail groove 244. Similarly, in an event that the processing unit 281 determines from the readings of the upper sensor 271 that the corresponding guide rail 210 has drifted toward the second side 248 such that the distance between the corresponding guide rail 210 and the second side 248 is less than a predefined distance threshold, processing unit 281 will effectively cause the upper, second magnetic guide 262 to increase the repulsive magnetic force exerted onto the corresponding guide rail 210 as compared to the repulsive force exerted onto the corresponding guide rail 210 by the upper, first magnetic guide 261. Again, this will have the effect of driving the ESA body 241 in the lateral or horizontal directions along the lateral or horizontal grooves 242 toward re-centering the corresponding guide rail 210 in the upper portion 245 of the guide rail groove 244.
With reference to
Technical effects and benefits of the present disclosure are the elimination of the wear and tear and the noise or vibration of gibs or rollers that are normally used to maintain ESA clearance from guide rails. In addition, the ESA guidance system can be independent of elevator speed and may allow for increased high speed displacement (e.g., in excess of 20 m/s).
While the disclosure is provided in detail in connection with only a limited number of embodiments, it should be readily understood that the disclosure is not limited to such disclosed embodiments. Rather, the disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the disclosure. Additionally, while various embodiments of the disclosure have been described, it is to be understood that the exemplary embodiment(s) may include only some of the described exemplary aspects. Accordingly, the disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Number | Date | Country | Kind |
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18305826.2 | Jun 2018 | EP | regional |